MANCHESTER, England (AP) — British Prime Minister Theresa May says progress is being made in the Manchester bombing investigation but the national threat level remains critical — meaning another attack may be imminent.

Speaking after a meeting of the government’s COBRA crisis committee, May said “the public should remain vigilant.” May said eight suspects are in custody and “progress is being made.”

The threat level for Britain was raised to its highest level after bomber Salman Abedi killed 22 people at a concert Monday night at Manchester Arena. Police say he was part of a network and they are racing to track down his links.

UPDATE – This incident has now been deemed safe and the cordon has been removed. Apologies for any confusion. pic.twitter.com/xdE9jqODeN